no title

Ashland County rock not a meteorite after all

View SlideshowRequest to buy this photoCOURTNEY HERGESHEIMER | DISPATCH PHOTOSAshland University geologist Nigel Brush knew he had something special when he found this rock in a streambed near the school. But it took an expert in St. Louis to pinpoint the rock and its origins.

ASHLAND, Ohio — The rock found in an Ashland County streambed had traveled quite a distance to
get there.

Just how far, however, would take several years to figure out.

This is a story about a geological mystery, one with possibilities that had Nigel Brush
excited.

Brush, an Ashland University geologist, typically takes a few students with him when he combs
area streambeds for rocks.

This time, something stood out. Brush thought he had found a piece of outer space.

“We thought it was a meteorite,” he said. “We took it back to our lab at Ashland and cut a slice
off of it to see what it looked like inside.”

The 11-pound rock wasn’t magnetic, which meteorites often are, so he put it on display in the
Kettering Science Building labeled
meteorwrongs.

Meteorite. Meteorwrong.

But this past spring, Brush looked at the rock again. He broke off a small piece and examined it
under a microscope. He saw tiny pieces of melted glass.

“It was possible it could be an impact breccia from the moon,” he said.

Impact breccias are made up of fragments of broken rock fused by a violent encounter of a
meteorite with Earth. And most lunar meteorites found on Earth are impact breccias that contain
glass, Brush said.

When a meteorite strikes Earth — sometimes as fast as 45,000 mph — some rocks break and some
melt. When the whole mess hardens, you’ve got impact breccia, said Dale Gnidovec, curator of the
Orton Geological Museum at Ohio State University.

“The shards are angular,” he said. “There’s quite a bit of mixture, and they’re included in a
fine-grain material.”

No lunar meteorites have been found in North America. That’s why they sell for around $1,600 per
gram.

That would make the rock Brush found worth about $8 million. “I was going to retire,” Brush
said.

He sent a picture of the rock to Randy Korotev, a research professor at Washington University in
St. Louis who specializes in meteorites. He told Brush it was a “definite maybe.”

Brush had a piece of the rock filed down until it was transparent, and then he attached it to a
slide and sent it off to Washington University.

“It’s very rare that people find a meteorite,” said Korotev, who has been asked more than 550
times this year to identify rocks people believe came from space.

In late June, Korotev got back to Brush and dashed his hopes. The rock was not from the moon.
The telltale sign? Quartz, which isn’t present on the moon.

“That turned out to be a meteorwrong,” Korotev said. But, “It turned out to be one of the
neatest meteorwrongs I’d ever seen.”

One of Korotev’s colleagues identified the rock as having formed at the Sudbury Impact Crater in
Ontario, Canada. In fact, he had a rock that looked exactly like Brush’s sample.

A giant meteorite smacked into Earth about 180 million years ago, forming the Sudbury crater,
one of the largest on Earth with a diameter of about 80 miles rim to rim, according to the
University of New Brunswick’s Earth Impact Database.

The only confirmed impact crater in Ohio is the Serpent Mound crater in Adams County. It
measures almost 5 miles across and was formed about 320 million years ago.

A meteorite has to be the perfect size to form a crater, Gnidovec said. Too small, and it burns
up in the atmosphere. Too large, and it vaporizes on impact.

“There’s a very narrow window,” he said.

So how did Brush’s rock get to an Ashland County streambed if it didn’t fall from space? An ice
sheet picked up Brush’s rock near the impact crater about 20,000 years ago and carried it south to
Ohio. That puts the value of the rock at about $80.

“We were right about impact breccia,” Brush said. “It was just from the wrong celestial
body."

Despite the letdown, Brush, who teaches a course on asteroids, comets and catastrophes, said he
knows there are lunar meteorites around. “They’re here,” he said. “We just have to find them.”